The invention is particularly well suited for coating wire tire cord wound on a spool, although the techniques involved are also applicable to coating a textile cord wound on a spool. It has been found more convenient and cheaper, from a cost standpoint, to coat the wire when it is on the spool rather than removing the wire from the spool before coating it.
Coiled wire armatures for motors have been coated by dipping them in vertically disposed vats of liquid coating material. In such cases, the armatures are first placed under a vacuum to remove any moisture. The vacuum is gradually decreased as the vat is slowly filled with liquid coating, under pressure, the pressure being utilized to increase penetration of the liquid coating into the interstices of the armature. It is necessary to lift the armatures into and out of the vats, thereby necessitating the use of expensive cranes and other equipment for handling the armatures, especially those of very large motors. Spools of wire tire cord are also large and difficult to handle. The invention is directed to providing a highly simplified apparatus in which spools of wire can be more conveniently handled as they are coated with a liquid.
Briefly stated, the invention is an apparatus for coating a continuous element, such as a wire tire cord, while it is wound on a spool which is used in the storage and transportation of the element. The apparatus comprises a chamber which is sealable from the ambient atmosphere. A trackway is provided for guiding spools through the chamber. The trackway is inclined from the horizontal such that the spools can roll, by gravity, along the trackway through the chamber. Means are supplied for circulating liquid coating through the chamber, for alternately creating a vacuum and pressure within the chamber to increase penetration of the liquid coating into the interstices or voids between adjacent segments of the element on the spool, and for drying the liquid coating on the element while the spool is still in the chamber.